The Methylation State Of NOEY2and TIMP3Gene In Intraductal Proliferative Lesion And Breast Cancer

Objective To investigate the methylation status of NOEY2gene promoter CpG island I and the promoter of tumor suppressor gene TIMP3,also its effects for the mRNA expression in breast cancer development.On the one hand to explore the correlation that methylation of NOEY2and TIMP3gene in breast cancer development,to further understand the mechanism of breast cancer. On the other hand to provide a reference for the choice of breast cancer gene methylation profile,and to provide a theoretical basis for early diagnosis,prevention and treatment of breast cancer.Methods1,DNA sulfite modification,methylation-specific PCR combined with sequencing technology were employed to detect methylation status of NOEY2gene promoter CpG island I and promoter of TIMP3in the breast cancer development.2, The mRNA expression of NOEY2and TIMP3gene in breast cancer were detected by real-time reverse quantitative transcriptase polymerase chain reaction.3,Rank test and rank correlation to analyze the correlation between gene methylation and its mRNA expression.4,The relevance between NOEY2and TIMP3gene methylation and clinicopathological parameters of breast cancer patients was examined by chi-square test.Results1,20cases of normal breast specimens were amplified the products of NOEY2methylation and unmethylation at the same time,were partially methylated.Complete methylation rate of benign breast hyperplasia specimens was6.7%(2/30), atypical hyperplasia was15.4%(2/13),carcinoma in situ was20%(4/20),breast cancer was32.6%(15/46).2,Among30cases of breast cancer specimens,9cases NOEY2mRNA expression which NOEY2CpG island I complete methylation were significantly down-regulation.19cases NOEY2mRNA expression were down-regulation and2cases NOEY2mRNA expression were up-regulation in other21cases of NOEY2CpG island I partially methylated specimens.The statistical analysis, NOEY2mRNA expression in complete methylated cases was significantly lower than in the partially methylated specimens.Between the two groups,there was significant difference(p<0.05).3,There was no correlation between NOEY2CpG island I complete methylation with other clinicopathological features of breast cancer,but NOEY2CpG island I complete methylation was a highly significant correlation with tumor TNM stage(p=0.041<0.05) and histological grade(p=0.035<0.05).4,20cases of normal breast specimens,30cases of benign proliferative breast specimens and31cases of breast precancerous lesion specimens,all these specimens TIMP3genes were not methylated. The methylation rate of breast cancer was10.9%(5/46).5, Among24breast cases,5cases which TIMP3gene was methylated,that TIMP3mRNA expression was significantly down-regulation.The remaining19unmethylated samples,15cases TIMP3mRNA expression was down-regulation and4cases was up-regulation which expression four times higher than normal expression and1case expresses mRNA normally.The statistical analysis,TIMP3mRNA expression in TIMP3methylation specimens was significantly lower than in unmethylated samples. Between the two groups,there was significant difference(P<0.05).6,There was no correlation between TIMP3methylation with other clinicopathological features of breast cancer,but TIMP3methylation was a highly significant correlation with tumor TNM stage(P=0.0005<0.05).Conclusions1,Abnormal methylation of NOEY2CpG island I does not exist in normal breast cancer.While we detected abnormal methylation in be ign breast hyperplasia,precancerous lesions and breast cancer specimens,and methylation rate was gradually increasd.This prompt that NOEY2CpG island I abnormal methylation existed in the early stages of breast cancer,and related to the development of breast cancer.2,Abnormal methylation of NOEY2CpG island I was relative to the loss of its mRNA expression.This indicated abnormal methylation of NOEY2CpG island I was an important mechanism of NOEY2inactivation in breast cancer.3,Abnormal methylation of NOEY2CpG island I was relative to tumor TNM stage and histological grade.This indicated abnormal methylation of NOEY2CpG island I played a role in the progression of breast cancer.4,TIMP3methylation only occurs in breast cancer, this indicated TIMP3methylation took place after mammary cell carcinogenesis,and it did not work in the early breast cancer.5,TIMP3methylation was relative to the loss of its mRNA expression.This indicated methylation was an important mechanism of TIMP3inactivation in breast cancer.6,TIMP3methylation was relative to tumor TNM stage,this show that TIMP3methylation associated with he progression of breast cancer.7,Methylation lead to NOEY2mRNA and TIMP3mRNA expression down-regulation only in partial breast cancer.This states there are other deactivation mechanisms except DNA methylation about NOEY2and TIMP3gene in breast cancer.